This invention relates to .beta.-lactam antibiotics. In particular, it relates to intermediates useful in the preparation of 1-carba(dethia)cephalosporin antibiotics.
In contrast to the cephalosporin antibiotics, which are prepared semi-synthetically, the 1-carba(dethia)cephalosporins have thus far been obtained only by total synthetic methods. For example, Christensen et al., U.S. Pat. No. 4,226,866, describe a method for preparing 1-carba(dethia)cephalosporins. Also, Evans et al., in U.S. Pat. No. 4,665,171, describe an asymmetric total synthesis of the amino-protected 3-hydroxy-1-carba(dethia)cephalosporin nucleus ester. Because of the growing importance of the 1-carba(dethia)cephalosporins as possible therapeutic agents for the treatment of infectious diseases, intermediates useful in the preparation of such antibiotics are of considerable value.